A SUSPICIOUS package sent to Celtic manager Neil Lennon had not gone through the proper postal procedures, a court has heard.

The brown padded envelope, addressed to Lennon at the club's training ground in Lennoxtown, East Dunbartonshire, had not been franked and the postage on it was "underpaid", the High Court in Glasgow was told.

Jurors heard that the package was intercepted at the Royal Mail sorting office in Kirkintilloch, East Dunbartonshire, on March 26, 2011 after a postman spotted a nail protruding from it.

Kim Riddoch, depot manager at the office, said she took it outside to the "furthest away point" from the building and contacted police.

She was giving evidence at the trial of Trevor Muirhead, 43, and Neil McKenzie, 42, who are accused of plotting to murder Lennon and high profile Celtic supporters by sending improvised explosive devices to them.

Ms Riddoch, 44, said she noticed the A5 package, which only had one first class stamp on it, was too heavy to reach its destination as it had been underpaid.

She told the court that the underpayment should have been detected by staff at the mail centre in Glasgow, where every item of mail in the west of Scotland is dealt with before being sent to local sorting offices for delivery.

She also said the franking process, which marks the date on a package, should have been done at the Glasgow centre.

Donald Findlay QC, representing McKenzie, asked Ms Riddoch: "So it is possible, I suppose, that this package entered the mail system at a later stage than say, being put through a post box or paid for at a post office?"

She replied: "That is not impossible."

Also giving evidence at the trial was Constable Gemma Currie, from Strathclyde Police, who was called to the Kirkintilloch sorting office.

She said she set up a cordon around the suspicious package, while specialist officers were drafted in to inspect it.

Pc Currie told the court that after the envelope had been ripped open, she was shown the contents, photos of which were shown to the jury today.

They included a bunch of more than 40 nails and an unmarked plastic bottle with a cloudy, milky liquid inside that Pc Currie described as having a slight "petrol or diesel" type of smell.

Police Constable Grant Wilson, who has training in evidential searching, was called to the scene to inspect the package.

He said he checked it to see if there was any "staining or sweating".

Advocate depute Tim Niven-Smith asked if he could clarify the significance of this, to which Pc Wilson replied: "When looking at a suspicious package, if it contains certain explosives they may excrete a substance and make the package look wet on the outside."

As there was no staining on the envelope, Pc Wilson told the court his superviser decided the package should be opened, which was done by his colleague Iain Baxter using a knife.

He said the contents included a small "travel" bottle with a size of about 100ml which held a milky substance, a wire, some nails and a white digital device with a clock face. The clock on the device was said to be "flickering like a calculator without much power".

Pc Wilson also told the court he took note of the package's "under-stamping".

When asked by Mr Niven-Smith why that might be significant, he said: "If it were over-stamped it may be the sender wanted it to go through the postal system without being noticed.

"But under-stamping could simply be an inexperience of the postal system, or it may be the sender did not want to raise suspicions as over-stamping might."

He explained that most post offices have CCTV cameras, and taking a package to one would mean the person sending it was "at risk" of being identified and traced back to the item they had dispatched.

The package was declared "not viable" at the scene and the contents of it were taken away by uniformed officers.

Later, the court heard that a suspicious package sent to former MSP Trish Godman's constituency office could have exploded under the correct circumstances.

Royal Navy bomb disposal expert Chief Petty Officer Lee Yates said a liquid inside a plastic bottle within the package had tested positive for the explosive substance tri-acetone tri-peroxide (TATP).

He said the liquid would normally be ignited with a power source such as a battery, but said it could have been triggered by light energy as the envelope was pulled open.

The court heard that prior to the incident, Ms Godman, who was the Labour MSP for the West Renfrewshire constituency, had worn a Celtic top to the Scottish Parliament as a "dare for charity" on the final day before Holyrood was due to dissolve pending the election which followed in May last year.

A package delivered to her office in Bridge of Weir, Renfrewshire, on Monday March 28 sparked the evacuation of the building.

Mr Yates, 48, was asked by advocate depute Tim Niven-Smith if the device had the "general appearance" of an improvised explosive device, to which he replied: "Absolutely. Anyone opening that envelope would get quite a fright I would think."

He went on: "It could have been part of a learning curve. It possibly could have been developed further if it had been allowed to go on. TATP usually comes in crystal format, like sugar. It is much more potent like this, putting it through the postal system in that state - it is unlikely it would reach its intended destination. Liquid is added to TATP to make it more stable.

"If it functioned in the way it was intended it could cause serious injury or even death, particularly because it contained nails which would act as shrapnel."

Muirhead, from Kilwinning, Ayrshire, and McKenzie, from Saltcoats, Ayrshire, deny all of the charges against them.